Как организовать приложение клиент-сервер на android?

/**
 * Выполняет GET запрос к http-серверу, 
 * возвращает JSONArray, либо JSONObject */
public static Object getJsonFromServer(String relativeUrl) throws Exception {
    URL url = new URL("http://example.com/" + relativeUrl);
    HttpURLConnection con = (HttpURLConnection) url.openConnection();

    int statusCode = con.getResponseCode();
    if (statusCode != HttpURLConnection.HTTP_OK)
        throw new IOException(con.getResponseMessage() + " (HTTP " + statusCode + ")");

    BufferedReader reader = new BufferedReader(new InputStreamReader(
        con.getInputStream(), Charset.forName("utf-8")));

    StringBuilder sb = new StringBuilder();
    try {
        String line;
        while ((line = reader.readLine()) != null)
            sb.append(line);
    } finally {
        reader.close();
    }

    String text = sb.toString();
    if (TextUtils.isEmpty(text))
        return null;

    return new JSONArray("[" + text + "]").get(0);
}